Automated tracking of energy balance in wild hummingbirds
Assistant Professor Kenneth Welch's study was published in Journal of Avian Biology and featured on the cover. The ingenious feeder stations were designed and constructed in the Welch lab to measure mass and bird ID while they feed. The study was conducted at U of T's Koffler Scientific Reserve.
Publication: Hou, Lily, Michael Verdirame, and Kenneth C. Welch. “Automated tracking of wild hummingbird mass and energetics over multiple time scales using radio frequency identification (RFID) technology.” Journal of Avian Biology (2015). Journal of Avian Biology 46: 1–8, 2015 doi: 10.1111/jav.00478
Chris Darling, Spencer Barrett and the students of the Tropical Field Biology course at the Alto Madre de Dios river (all photos courtesy of Chris Darling)
Herbivore dispersal experiment
Historically, ecologists have debated the relative importance of dispersal and local species interactions (such as competition and predation) in structuring biodiversity. Recent advances have shown that these two processes often work in conjunction to produce surprising results, yet most research has remained focused on local interactions. This is particularly true in the case of global change studies, where scientists have focused on how changes to temperature or rainfall alter competitive dynamics. In this study we use common milkweed (Asclepias syriaca) and its community of specialist herbivores to understand how temperature change will alter insect communities through effects on both local dynamics and dispersal among milkweed patches.
We accomplish this by creating milkweed patches with known abundances of herbivores that are adjacent to unoccupied patches at various distances. Both the focal and unoccupied patches are surrounded by an insect net enclosure, and both are either warmed (ambient +2.5°C) or established as controls (ambient temperature). Our results will show how warming effects the impacts of herbivores on plants and on each other, and how these impacts are influenced by warming-induced changes to dispersal rates. This will be one of the first experiments that quantifies the effects of warming on biodiversity via its independent and interactive impacts on local interactions and dispersal.
Invertebrate community sampling in
Georgian Bay Islands National Park
EEB post doc Shannon McCauley samples invertebrate community in pools from the Georgian Bay Islands National Park. This study was desgined to assess the extent to which these communities are structured by habitat isolation and local habitat conditions. This work was enabled by a grant from the National Geographic Committee on Research and Exploration to Shannon McCauley and Marie-Josee Fortin. Graduate student Aaron Hall was also part of this research team and his work is exploring the effects of these conditions on the coastal communities on odonates on these islands.
Shannon McCauley is now Assistant Professor in the Biology Department at University of Toronto, Mississauga. Students and postdocs interested in joining the lab should contact me directly (shannon.mccauley ‘at' utoronto.ca) to discuss possible research projects and funding.
PhD candidate Kyla Ercit from the Gwynne lab is studying wasp feeding behaviour at Koffler Scientific Reserve at Jokers Hill. A wasp Isodontia mexicana , carries a paralysed female tree cricket, Oecanthus niveus , back to her nest to feed to her young. Photograph by Gil Wizen, August 2011. The Gwynne lab uses insect wasp and bee trap-nests to study insect interactions.
Transplant preparation at KSR
Undergraduate students prepare plants in the greenhouse at Koffler Scientific Reserve at Jokers Hill . These plants will soon be transplanted to field sites to be used in experiments on the evolution of flowering phenology. PhD Candidate Susana Wadgymar uses Chamaecrista fasciculata to investigate plastic phenological responses to artificial climate warming, while PhD candidate Emily Austen uses Brassica rapa to examine selection on flowering time via male fitness. Both projects are ongoing, with publications expected in 2013.
Using a combination of field and laboratory studies, the Rodd lab is testing frequency-dependent mating and survival advantages that could maintain genetic variation in male colour pattern. Males with rare colour patterns have been shown to have a survival advantage. Current research is designed to examine factors that could contribute to this advantage.
PhD student Alison Parker from the Thomson lab ran a pollinator camp for a number of Undergraduate students. The students shown here (Rosa, David & Sarah) caught and identifying pollinators visiting flowering plants at our field station (KSR). This field work was part of a Research Opportunity course EEB299.
Do Medicago truncatula genotypes impose selection on Nitrogen-fixing rhizobia strains?
PhD candidate Rebecca from the Frederickson Lab planted a greenhouse experiment to test whether host (Medicago truncatula) choosiness imposes selection for N-fixation in a mixed population of rhizobium strains. Based on a previous experiment (currently in-prep for submission), Rebecca found significant genetic variation for host lines in their ability to form associations with effective N-fixing rhizobia. The next question is whether genetic variation in this heritable host trait, thought to be important for maintaining mutualism stability, will alter the frequencies of two rhizobium strains, one good at fixing N (Ensifer meliloti 1022), and the other, not so good (Ensifer meliloti 1021). After four host generations (~ 9 months), Rebecca will quantify the degree to which strains were released into the soil (using quantitative molecular methods), to get an accurate estimate of rhizobium fitness.
Evolution of sex chromosomes in Rumex hastatulus
Rumex hastatulus males from North Carolina, USA have two Y sex chromosomes, while those from Texas only have one. Are these extra Y chromosomes parasites, advantageous to their carriers, or there just by chance? Felix Beaudry and Professor Stephen Wright are creating a linkage map for R. hastatulus: by raising and sequencing the DNA of 200 offspring from the same parents for each race, they hope to find out where recombination (mixing of genes between chromosomes) events occur and how this influences the different Y chromosomes. This will help them to find the genomic locations of genes important to sex, and whether some Y chromosomes can transmit themselves despite a fitness cost to their host.